GMC 1997 Safari Owner's Manual page 286

Thermostat
Engine coolant temperature is controlled by a thermostat
in the engine coolant system. The thermostat stops the
flow of coolant through the radiator until the coolant
reaches a preset temperature.
Power Steering Fluid
When to Check Power Steering Fluid
It is not necessary to regularly check power steering
fluid unless you suspect there is a leak in the system or
you hear an unusual noise. A fluid loss in this system
could indicate a problem. Have the system inspected
and repaired.
How To Check Power Steering Fluid
When the engine compartment is cool, unscrew the cap
and wipe the dipstick with a clean rag. Replace the cap
and completely tighten it. Then remove the cap again
and look at the fluid level on the dipstick.
The level should be at the FULL COLD mark. If
necessary, add only enough fluid to bring the level up
to the mark.
What to Use
To determine what kind of fluid to use, see
"Recommended Fluids and Lubricants" in the Index.
Always use
the
proper fluid. Failure to use the proper
fluid can cause leaks and damage hoses and seals.
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